Experimental Study on a Line-Axis Concentrating Solar Energy Collector for Water Heating
Frederick Ikpakwu,
Anthony Okoronkwo,
Modestus Okwu,
Emmanuel Anyanwu
Issue:
Volume 3, Issue 6, December 2017
Pages:
62-69
Received:
29 March 2017
Accepted:
6 June 2017
Published:
28 November 2017
Abstract: This paper examines the experimental study on a line axis concentrating solar energy collector for water heating. The system considered consists of cylindrical solar radiation concentrator with a black coated tubular absorber positioned along its axis. A cold water tank is placed above the collector and a hot water tank positioned below it such that fluid flows in and out of the set up. Solar radiation absorber inlet header is connected to the cold water tank while its outlet header is connected to the hot water tank. These major components are supported by angle iron raised at a distance from the ground that depends on the location and function. Valves are used at strategic points on the connecting pipe lines to isolate the flow of water. When water is poured into the cold water chamber, and the control valve turned on, the water flows under gravity into the receiver/absorber tube. At the absorber section, heat is transferred from the steel tube to the circulating water and is consequently heated. The heated water, then flows into the returning tube against gravity, thereby restricting the heated water from flowing into the storage tank. At this stage, thermo-siphoning effect comes into play. As the temperature of the water increases, its density reduces while the mass remains constant in order to balance the effect of the reduction in density. Thus, there is a resultant increase in volume which consequently pushes the water level further along the returning pipe. Further increase in temperature reduces the water density and increases the volume of the water, thereby causing the heated water to flow into the insulated tank. Several experimental tests were carried out under meteorological condition at the Federal University of Technology Owerri, Nigeria at three different mass flow rates of 0.001kg/s, 0.002kg/s and 0.003kg/s. The solar water heater was tested while oriented in the East–West and North –South directions in order to determine the effects of orientation on the performance. Results obtained showed that a maximum temperature of 69.5°C, corresponding to 34.5°C increase in water temperature and a maximum instantaneous efficiency of 51.01% is possible. The aim of the study is to design a cheaper solar energy system capable of reducing energy bill within the developing countries of the world.
Abstract: This paper examines the experimental study on a line axis concentrating solar energy collector for water heating. The system considered consists of cylindrical solar radiation concentrator with a black coated tubular absorber positioned along its axis. A cold water tank is placed above the collector and a hot water tank positioned below it such tha...
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Pressure Effect on Superconducting Critical Temperature According to String Model
Ibrahim Adam Ibrahim Hammad,
Mubarak Dirar,
Nadia Omar Alatta,
Rasha Abd Alhai Taha,
Kh. M. Haroun,
Rawia A. Elgani
Issue:
Volume 3, Issue 6, December 2017
Pages:
70-74
Received:
2 March 2017
Accepted:
31 March 2017
Published:
28 November 2017
Abstract: Superconductivityis generally regarded as one of the most striking and widely used physical phenomenon. Physicists in response have shown sheer interest in scrutinizing superconductivity and constructing theoretical models to explain it. The majorityof models derived in this regard neglected some aspects of superconductivity. The link between critical temperature and pressure remains a highly neglected and potentially representing a research gap in this area. Thus, this motivates the researchers to construct a new model on the relation between pressure and superconductors critical temperature using a string model. The study mainly aims to construct theoretical model based on string model in attempt to understand the effect of pressure on critical temperature and superconducting resistance. The results of study reveal that using plasma equation for mechanical and thermal pressure the frequency is obtained. It also finds that treating electrons as string the energy is found in terms temperature and pressure. Further, when the superconducting resistance vanishes the corresponding critical temperature was found. Furthermore, the increasing mechanical pressure increases the critical temperature.
Abstract: Superconductivityis generally regarded as one of the most striking and widely used physical phenomenon. Physicists in response have shown sheer interest in scrutinizing superconductivity and constructing theoretical models to explain it. The majorityof models derived in this regard neglected some aspects of superconductivity. The link between criti...
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The Tubing Destruction Features in Operation of the Gas Condensate Fields with Corrosive Fluids High Content
Nazarii Chaban,
Valentyn Myndiuk,
Oleg Karpash
Issue:
Volume 3, Issue 6, December 2017
Pages:
75-81
Received:
20 March 2017
Accepted:
13 April 2017
Published:
16 January 2018
Abstract: This of article is devoted to solving the problem of determining the actual mechanism of corrosion caused by the influence of corrosive environment with high pressures and temperatures on the tubing pipe metal, during high depth condensate fields development, with a high content of hydrogen sulfide and carbon dioxide in the fluid. The of results of the actual state evaluation of tubing pipe specimens are presented, the causes and nature of the corrosion damages and the mechanisms of their progress in the given conditions are identified. In particular, the of results of visual and instrumental investigation shows, that corrosion of the tubing surface has local (zone) nature; corrosion processes occurs as on interior as well on exterior tubing surface, whereby interior surface has the presence of corrosion deposits in local zones and also pitch zones, and exterior surface corrosion is present only by pitch corrosion. The local corrosion on the tubing surface is caused by carbon dioxide carrion. The main impact factor is the presence in gas-liquid mixture the molecules of СО2 and Н2СО3 and ions НСО3- and HСО32-, as a result of carbon dioxide gas dissolving, which activate the environment corrosive aggressiveness.
Abstract: This of article is devoted to solving the problem of determining the actual mechanism of corrosion caused by the influence of corrosive environment with high pressures and temperatures on the tubing pipe metal, during high depth condensate fields development, with a high content of hydrogen sulfide and carbon dioxide in the fluid. The of results of...
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